1. Technical Field
The present invention relates to a so-called pinch grip type bottle-shaped container, which is formed with opposed recesses at a main body portion of the container body such that the recesses are used as a grip part for gripping the container, and intends to advantageously avoid lowering of the mechanical strength due to a light-weighted or thin-walled nature of the container.
2. Related Art
Synthetic resin containers, such as PET bottles, have been widely used as containers, e.g., for filling therein foods, beverages, cosmetics or medicines, since such containers are light in weight and can thus be easily handled, have transparency to exhibit a refined appearance comparable to glass containers, and can be produced at low cost.
Synthetic resin containers have a relatively low mechanical strength against external forces. Therefore, when the container is gripped at its main body portion for pouring the contents out of the container, the container inevitably undergoes deformation at its gripped part.
It is thus a typical countermeasure to appropriately control the container wall thickness and form longitudinal ribs, lateral ribs or waists (i.e., circumferential grooves surrounding the main body portion) so as to improve the resistances of the container to external forces, such as rigidity, buckling strength, etc.
However, there is an increasing demand for thin-walled (or light-weighted) containers so as to reduce the resin amount to be used per one container from a standpoint of effective utilization of resources and reduction in the amount of wastes, resulting in a situation where the strength of the container is inevitably further lowered in order to deal with such a demand.
Particularly, in the case of pinch grip type large-sized containers, which have been recently used widely as large-sized containers having a filling volume of not less than 2.7 liters, for containing therein Japanese “sake”, soy sauce, edible oil, Japanese “shochu” (distilled spirit), whisky, etc., when it is desired to realize light-weighted structure, the container main body portion including the grip part inevitably undergoes deformation when gripped at the grip part.